1. Field of the Invention
The present invention relates to a structure for mounting a coin-filter filtering foreign materials such as dust or mote contained in hydraulic fluid on a fixing groove without using an O-ring. More particularly, a coin-filter surrounded by a holder is placed in a fixing groove formed at an inlet side of an orifice, and the holder is fixed to the fixing groove through plastic deformation by an outside power.
2. Description of the Related Art
Generally, since the heavy equipment including excavator is used to lift a lot of foreign materials such as dust or soil dust owing to the proper characters of heavy equipment, the hydraulic fluid in a hydraulic tank is polluted with the foreign materials.
If the hydraulic fluid polluted with foreign materials is not suitably purified, the efficiency of the heavy equipment is lowered or the parts such as hydraulic cylinder to which the hydraulic fluid is supplied are damaged by the foreign materials contained in the hydraulic fluid and thereby the life span of actuators is shortened.
As shown in FIG. 1, a coin-filter according to the conventional art comprises a body 3 having a fixing groove 2 formed at an inlet side of an orifice 1, a coin-filter 4 fixed at an inside of the fixing groove 2 for filtering foreign materials such as dust contained in hydraulic fluid, and an O-ring 5 tied to the fixing groove 2 for preventing the detachment of the coin-filter 4 from the fixing groove 2. In the FIG. 1, the reference numeral 6 denotes a holder supporting the outside of the coin-filter 4.
The above structure for mounting the coin-filter needs an O-ring 5 for fixing the coin-filter 4 to the fixing groove 2, results in the increase of manufacturing cost by increasing pertinent parts' number. So the competitive power is lowered in the aspect of price, and also the working efficiency is lowered since it is difficult to insert the O-ring 5 into the narrow fixing groove 2. Further, it is another problem that a size of the fixing groove 2 becomes big since a special fixing groove 2 should be formed in a body 3 for fixing said O-ring 5.